380 BRITISH FOSSIL REPTILES. 



the axis of the jaw ; the plane of the outlet incUnes shghtly outward (fig. 1, c). The 

 interval between two sockets is about half the long diameter of each. On one side 

 of the figured specimen the fifth socket is obliterated. The anterior termination of 

 the jaw is obtuse ; the sides are smooth, flat, converging at an acute angle to what 

 almost forms a ridge above (fig. \,c,d) ; the jaw gradually increases in vertical diameter 

 as it proceeds backward, the upper contour being straight as far as it can be traced 

 in the fossil. The palatal surface is entire, narrowest between the second sockets, 

 suddenly broader and flat between the third pair, retaining about the same breadth, 

 but with a slight convexity and feeble indication of a median ridge in the rest of its 

 extent, the ridge not being so strongly marked as it appears in fig. 1, b. 



The Pterosaurian nature of this fossil is shown by the extreme thinness of the 

 compact bony wall of the jaw ; its relation to the genus Pterodactylus, as contra- 

 distinguished from the Rhamphorhynchus, V. Meyer, is proved by the terminal posi- 

 tion of the sockets ; and sufficient of the outer side wall of the jaw is preserved to 

 show that the nostril did not advance so far forward as in Dimorphodon — the generic 

 form of Pterodactyle from the Lower Lias. 



By its size and proper Pterodactjle affinities the present specimen most 

 resembles Pterodactylus Cuvieri of the Chalk, (p. 242, PI. 3, figs. 1 — 7) ; but it 

 offers the following well-marked differences : a greater proportional size of the 

 anterior sockets, with a corresponding expansion of the fore part of the jaw ; a 

 greater number and closer arrangement of the sockets ; a greater depth of the jaw, 

 in proportion to the breadth of the palate. The extent of the jaw, e. g., containing the 

 first seven sockets, in Pterodactylus Sedgwiclii, is 2 inches 9 lines ; but in Pterodactylus 

 Cuvieri it is 3 inches 6 lines : the depth of the jaw, above the third socket, in Pter. 

 Sedgwickii, is 14 lines ; in Pter. Cuvieri it is 8 lines ; whilst the breadth of the palate 

 between the third pair of sockets is only 1 line less in Pter. Cuvieri than in Pter. 

 Sedgwickii. It needs only to compare the fore part of the jaw of the Great Chalk 

 Pterodactyle (PI. 3, figs. 1 — 4) with the same part of the still larger species from the 

 Grreen-sand (PI. 7, figs. 1 and 2), to be convinced of their specific distinction. 



The difference is still more marked between Pterodactylus Sedgwickii and 

 Pterodactylus coinpressirostris (PI. 3, figs. 8, 9, 10). The rapid increase of depth 

 as the jaw extends backward, in Pter. giganteus, Bk. (PI. 6, fig. 1), shows that 

 that comparatively small species cannot be the young of the present truly gigantic 

 Pterodactyle of the Upper Green-sand. I have no hesitation, therefore, in basing 

 on the above-described fossil a new species, at present the largest known in the order 

 of Flying Saurians, which I propose to dedicate to the Woodwardian Professor of 

 Geology in the University of Cambridge, who for forty years has discharged the 

 duties of that office with exemplary zeal and a rare eloquence, has almost created the 

 museum still called " Woodwardian," and has enriched geological science by original 

 researches which have thrown light on its most obscure and difficult problems. 



